Machine for drilling drawing dies or stones



1927' s. LOEWENHERZ MACHINE FOR DRILLING DRAWING DIES 0R STONES Filed A112. 20. 1925 Patented July 19,1927

UNITED STA TES PATENT OFFICE.

smemnm Lonw'nnnnnz, or nnnnm, enmity, asarenon 'ro PATENT-resonanenennnscm'r run nLExrnIscnn GLUHLAIPEN I. '3. IL, or BERLIN, enemy,

A CORPORATION 01' GERMANY.

MACHINE FOB DRILLING Application filed August 20, 1925 Serial No.

This invention relates to a machine for boring or drilling drawing dies or discs, in particular diamond drawing dies, in which a rod-like holder adapted to be reciprocated 5 and carr in the work, e. g. the stone, is retracted mec anically at short intervals of time from a rotating drill and is pressed by spring pressure again into contact with the drill.

In such machines hitherto it has been necessary at very short intervals of time, say every 15 to 30 minutes, to see that the drill is replaced or reset, as owing to wear occurring there is the liability of the hole to be as bored being widened by the thicker part or shaft of the drill.

The invention has for its object to avoid the necessity for continuous attention to the boring operation by the attendant as regards as watchin for Wear of the tool. and accord-. ingly o avoiding the dangers of such continuous inspection. For this purpose, in accordance with the invention, a limit is set to the extent of the feed movement of the Work holder required dependent upon theermissible wear of the drill and the increase in depth of the hole by a stop adjustably arran d in the path of movement of the work hol er. This step is adjusted before the machine is started, and after the work holder takes up contacting position with the drill, by the amount of the permissible wear of the drill from the projecting part of its holder, so that immediately on wear of the drill ocas curring, or shortly before such amount of wear occurs, the stop strikes the projecting part of the holder, preventing further feed movement of 'the work holder. Even should the operator not notice in due time that the re drill has worn, no widening of the hole being drillfl will occur.

In order that the operator may be automatically notified of contact occurr' and of the drill having become worn, both t '5 stop ed and the work holder or a second stop mounted thereon are interposed in an electric circuit which is closed on contact between the sto s occurring and operates one or more signa g devices, lamps, bells, drop signals or the like, attracting the attention of the .operator. Also, by the closure of the electric circuit the mechanism effecting the withdrawal of; the drill may also be started and, if desired, also the drill may be stopped, so

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that. when contact between the stops occurs all movement of the work and of the drill ceases.

A machlne in accordance with the invention is illustrated by way of example in the accompanying drawing in Fig. 1 in elevation and in Fi 2 in plan. In Fig. 3 is an end view and i 4 and 5 are plan and an end v ew respectively of details of the machlne 111 other positions.

As shown, on the machine frame a is mounted in a bearing 6, a spindle 11 carrying the drill 0, which spindle d is set in rotation by the belt pulley e. Axially of the drill 0 is mounted adjustably on rollers f a rod g to the forward left hand end of which the die or the stone 7:. to be drilled is soldered in the usual manner. The rod-like work holder 9 1s provided on its upper side with notches i in which engages a blade spring Z secured to an adjustable holder k. The spring 1 tends to press the work holder and thus the die or stone forward into contact with the drill a. On the lower side of the holder g is secured a pm m against which bears one arm of a rock-lever o operable by a rotary cam n. By means of this cam the holder 9 and thus the stone h is retracted fromthe drill 0 against the action of the spring I at definite uniform t me intervals. A to and fro motion in relat on to the rotatin drill is thus imparted to the work or stone the spring Z and by the cam n. Due to t e contact of the work holder with the pointof the drill in conjunction with the continuously exerted friction, the drill point is worn to a definite extent in a short time. To this wear corresponds a definite advance of the work holder under the action of the spring. This much of the mechanism is well known and has been described to enable a clear understanding. of my invention.

Parallel to the rod-like work holder 9 is a small bracket p secured to a block of insulating-material 1, held to the frame a by screws 2. In this bracket is adjustably mounted the rod 9 which is held pressed by the spring with its right hand end in contact with a stop plate 8 held in the insulating plate 1 by screws 3.. Between the end of the rod and the stop plate a is adapted to be inserted a plate t secured to a rotatable lever u.

latter issecured a rod '22 which on ro- To the tation of the lever 14 is pressed against the a by inserting the blade spring Z in one of the notches i on the work holder, and thereupon the contact ring to is adjusted on the rod gas shown in Fi s.1 to 3 in such manner that it bears agalnst the stop :0 on the work holder 9. The lever u is then turned in the direction of the arrow 3 whereupon the plate 6 secured thereto is inserted between the spring pressed end of the rodg and the stop plate 8 and the rod g with the 1 ring w thereon is displaced to the left an amount corresponding to the thickness of the plate t. As such thickness corresponds to the maximum allowable wear of the drill,

on insertion of the plate t the ring w is moved away from the stop an by an amount corresponding to such maximum allowable wear. In this position the ring to is held firmly by the clamping rod which is raised on rotation of the lever u. The machine may now be set in motion by engaging the drill a and the device for positively retracting the work holder. As the drill becomes wornthe distance between the two stops 'w and a: becomes less until after a definite interval of time, i. e., when the maximum allowable wear of the drill has taken place the two stops w and a: come in contact. No further movement of the work holder can take place so that even should the attendant omit to' observe that the two stops had come in contact no further wear of the drill liable to cause damage would occur.

Preferably the two stops 'w and :u' serve also as contacts of an electric circuit in which one or more signal devices (lamps, bells, drop signals or the like) are inserted. In such c rcumstances on the two sto s contacting the attention of the atten ant is automatically obtained bythe signal or signals.

Connected to the bracket p, (for example by one of the screws 8 that connect this" bracket to the insulatin block 1,) is one end of a normally open e ectric circuit 4, the other end of .which'is cdnnected to a non-insulated part of the machine, conveniently toone of the bearing ins for one of the rollers f at 9. This circuit contains a source of current 5, an audible signal as a bell, 6, and a visible signal, for example a lamp 7. The arrangement is such that when pin :0 contacts W1th.Whe61 w the circuit is closed and the signals operated.

The invention is not limited to the details described. For example, in lieu of the, arrangement shown in the drawing a movable and adjustable stop may be provided on the work holder g a fixed stop on the rod g stones and which will then be stationar In lieu of adjusting and securing in ad usted position I one stop, both stops may'be adjustable. The adjustment and the securing in adjusted position of the stop or stops may be effected in .any other way, for instance by means of a screw threaded spindle drive. The retraction of the work holder may be effected by any other convenient means instead of by a cam as shown. The distance piece t is preferably detachably secured to the lever u so that according to the fineness of the drill point and the length of point required blades t of different thickness may be employed.

.1 claim:

1. In a machine for drillin precious articularly diamon drawing dies, a non-feeding rotary drill holder, an alined work holder lon itudinally reciprocated, a spring urgin t e work holder and work against the dril nieans for retracting the holder in rapid succession a ainst the action of said spring, a stop on the holder, a rod arranged parallel to the work holder and a stop on the rod co-operatin with the stop on the holder, one of whic stops is adjustable and determines the limit of feed of the holder.

2. In a machine for drillin recious stone and particularly diamond drawing dies, a non-feeding rotary drill holder, an alined work holder, a spring ur ing the -work holder and work against. t e drill,

means for retracting the holder in quick succession against the action of said 3 ring, a rod arranged parallel-f the hol er, a wheel adjustable along saidfiirod and a stop on the holder arranged to strike the wheel, the adjustable distance between the said stop and wheel being less than the stroke of the holder as determined by said cam.

3. A machine for drilling drawing dies or stones and in particular diamond dies, including a drill a work holder ada ted to be moved to and fro relatively to sai drill and means for limiting the forward movement of the work holder, said mea including a rod disposed adjacent the '"wor holder, a stop adjustably mounted on said rod and a co-operating stop mounted on said work holder and means for positioning said rod and consequently said first mentioned stop including a stop plate normally enga ed by said rod and a distance piece adapte to be inserted between the rod and the'said stop plate substantially as and for, the purpos set forth.

4. A machine for drillin drawing dies or stones and in particular 'amond dies, in-

cluding a drill, a work holder'adapted to-be moved to and fro relatively to said drill and means for limiting the forward movement of the work holder, saidmeans including a rod disposed adjacent the workholder a stop ad justably mounted on said rod-and a stop on said work holder, and means for positioning said rod and consequently said first men tioned stop including a stop plate normally engaged by said rod, a lever arm and a distance piece detachabl secured to said lever arm and adapted to v e interposed between said rod and said stop plate by movement of'said lever arm. 1 v

5. A machine for drillin drawing dies or stones and in particular iamond dies, in-

' eluding a drill, a work holder adapted to be moved to and fro relatively to said drill and means for limiting the forward movement of the work holder, said means including a rod disposed adjacent the work holder a stop adjustably mounted on said rod and a stop on said work holder, and means for positioning said rod and consequently said first mentioned stop includin a stop plate normally engaged by said r0 a lever arm and a distance piece detachably secured to said lever arm and adapted to be inter ed between said rod and said stop plate y movement of said lever arm, said lever arm also fitted with means to clamp said first mentioned stop on said rod.

6. A machine for drilling drawing dies or stones and in particular diamond dies, including a drill, a work holder ada ted to be so moved to and fro relatively to sai drill and have but in the path of the first mentioned stop so that on wear of the drill occurring the stops come in contact, said sto s being interposed in an electric circuit an on contact occurring closing such circuit and signal devices adapted for actuation on closure of such circuit.

7. A machine for drilling precious stones,

articularly diamond drawing dies, comprismg a rotating drill holder, an alined work holder and means for continuously reciprocating the work holder, in combination with a stop on the work holder and a second relatively stationary stop to be engaged thereby, movable supporting means for the second stop and a gauge plate corresponding in thickness to the permissible wear of thedrill and pivotally arranged to be inserted between said supporting means and a stationary portion of the machine after said stops been set in' contact preparatory to startin the drilling o ration.

n testimony t at I claim the foregoing as my invgntion, I have si ed m name.

IEGMUND EWE RZ. 

